The Reporter: February 1996, Vol.7, No.1
Research Notes

Study Finds Gene Blocks Cell Growth

Four microbiology and medicine researchers have conducted a study that offers fresh insights into how vpr, a gene of HIV, stops cell growth. A research team led by Dr. Jeremy Luban, P&S assistant professor of microbiology and of medicine, published it s findings in November 1995's Journal of Virology. Others on the team were Fabio Re, Douglas Batten, and Ettaly Kara Franke.

The researchers discovered that vpr stops cells from replicating by blocking the process of cell division at a specific stage just after the cell has copied its DNA but before it has divided.

According to the study, the gene appears to stop cell growth by blocking a cascade of reactions that signal a cell to begin mitosis. "We believe that vpr makes the cell think it is not ready to go into mitosis," says Dr. Luban. That is accomplished when vpr blocks the activation of p34ede2, a cellular protein.

"We still don't know why blocking cell division in G2 would be an advantage to HIV," says Dr. Luban. One possible explanation is that vpr stops cell growth in G2 because that stage is important to the HIV virus. For instance, there may be specific transc ription factors particularly abundant at G2. Or the G2 stage may protect the cell so that it doesn't die, allowing more HIV to be produced. Finally, it is equally likely the arresting of cell growth has no real relevance to the replication of HIV but is s imply a secondary effect.

"Heart Boost" Contract

P&S has been awarded a five-year, $4,350,000 contract from the National Heart, Lung and Blood Institute to develop a ventricular assist device. CPMC will work in collaboration with Abiomed, a Massachusetts-based developer, manufacturer, and marketer o f advanced heart support systems. The device, temporarily dubbed the "heart booster," is designed to treat congestive heart failure.

"This device is targeted at the increasingly large population of patients with moderate to severe congestive heart failure," says Dr. Eric A. Rose, chairman of surgery and co-principal investigator.

The heart booster will surround the outside of the heart and assist its pumping action. Unlike other devices, such as artificial valves, the heart booster will not contact flowing blood.

Preliminary designs for the booster will be tested in preclinical studies at CPMC. The researchers estimate that tests on humans may begin in five years. The final design will be fully implantable in the body and the researchers hope to design the booster so that it can be implanted with only a small incision.